It is known to provide clamping devices for the aforedescribed purposes which can consist of an upper crossbar or traverse, a lower crossbar or traverse and tensioning bolts connected to these two traverses, i.e. so-called drawbolts. The upper and lower traverses have surfaces which are adapted to engage directly the upper and lower surfaces of the conveyor belt. A support can be provided for the entire assembly. The drawbolts can be tightened by a torque wrench to prescribed torque settings and hydraulic actuators can be provided for them if desired.
Since the drawbolts flank the belt and act at the ends of the traverses, the latter are subjected to a more or less arcuate elastic deformation so that the clamping force and hence the belt-holding force is not uniformly distributed over the entire lengths of the crossbars.
The edges of the conveyor belt may be clamped more strongly or tightly than central regions of the conveyor belt and frequently the edge regions can show damage resulting from excessive local clamping force. The mounting for the assembly is attached directly to the crossbars or to one of them. As a result, the crossbars may be subjected to a complex stress pattern which can impair the stability of the clamping device when high tensile forces are applied to the conveyor belt. Should the system break down, there is danger to personnel as well as to the product being clamped.